Where to start with steppers and stepper drivers?

Hi there,

I'm building some gauges for a cockpit simulator build and I will need to use some stepper motors. I've done some google-ing but literally every tutorial is using a different motor and a different driver so yeah, I'm really confused now. Could someone please point me in the right direction for a cheap stepper motor (doesn't have to be powerful at all) and a driver to control it with?

Thanks, Matthew

To give you an advice we need some more details about what you are going to achieve. So let us know, 1. how fast the steppers should be (e.g. full turn in .... sec) 2. is space a factor 3. what about your power supply

I understand that torque is no issue, but the above listed parameters might matter, besides of those which we hopefully will get to know, when you give us a little more background information.

Sure.

  1. The motors will be pretty slow, maybe 1 seconds at the fastest for a full turn, keep in mind though not all the gauges actually make a full turn so it's kind of hard to know.

  2. Yes but I imagine the steppers would be relatively small so it shouldn't be a problem. Each gauge is roughly 7cm wide (circle shaped).

  3. What about my power supply? What should I be using for these? The arduino's them selves will just be plugged into the computer with a usb feeding in/out data from the simulator in the serial ports but they will be powering a lot of things such as buttons/leds/switches/motors...I do have a 5v 5a power supply (link below) though that I picked up for like $5, would this work: https://www.aliexpress.com/item/High-Quality-AC100V-240V-to-DC5V-5A-25W-Voltage-Transformer-Switch-Power-Supply-for-Led-Strip/32616459483.html?spm=2114.01010208.3.191.scv34W&ws_ab_test=searchweb0_0,searchweb201602_2_10056_10065_10055_10068_10054_10069_10059_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_7&btsid=5a022e1b-a30f-4cef-8b42-781c60124b77

Have a look at these links to get you started Stepper Motor Basics Simple Stepper Code

...R

Where will the simulator be used? I suspect, in a kind of laboratory, but not in any vehicle?

So the only space-critical things would be the steppers themselves, as you want to drive the hands of the gauges directly on the axis of the steppers?

If this is true, and you want to mount the steppers directly into a gauge case, the limiting factor is found and your steppers can't exceed 7 cm (diagonal), right?

Another possibility would be to mount them behind a gauge if depth is no issue for the cockpit simulator. But: As the steppers won't have to carry big loads - in fact it will be like idle load, just moving hands - torque is no issue at all and you could go with pretty small steppers.

As I am in a hurry right now, I will look something up tonight. In the meantime let us know if all my assumptions are correct.

Ok, I searched the sizes for NEMA steppers: NEMA 11 = 28mm square = 39mm diagonal NEMA 14 = 35mm square = 49mm diagonal NEMA 17 = 42mm square = 59mm diagonal NEMA 23 = 57mm square = 79mm diagonal

Theoretically you could go up to a NEMA 17 sized stepper. But, if my assumption is correct that you only want to move small hands on the shaft of the motor, you could go with the weakest NEMA 11 stepper - you could even go with something like this: https://www.adafruit.com/product/918

plus an adequate driver.

To continue you should come back with some confirmations about my assumptions and the knowledge about steppers in general, having studied Robin2's information.

Once we have identified the right stepper motor we can care about the driver boards and the power supply for your project

Perhaps these. - Scotty

matthewinglis: I'm building some gauges for a cockpit simulator build and I will need to use some stepper motors

I just realized I missed this - the most important bit - apologies.

You can get some very small stepper motors that are specifically intended for instruments. These are just two links that I kept. No doubt there are many others analog-gauge-stepper-breakout-board 4-Wire-2-Phase-Mimi-stepper-motor

...R PS... @scottyjr's link looks like it may be better.

Wow, never heard of those tiny steppers especially for gauges.
Good information for me for the future as I was looking for very small gauges for a test pad and all the gauges which I could find were way too big and I didn’t want to use digital displays for certain reasons.

Thanks guys for the replies!

@rpt007 The simulator is just a fun project, it will probably be in my room, but I don't really know yet. 7cm is just a guess at this stage, I haven't got any dimensions yet but that's my guess. The gauges are circle too, so I think the word you'd be looking for is diameter, not diagonal. Depth isn't an issue no, but I don't want anything ridiculous if you know what I mean.

Some of those Nema motors look pretty good but they're a little bit pricy for just a couple of gauges. However those adafruit ones look pretty nice, very small and cheap. I think I would go with those? What do you think?

@scottyjr Those also look very nice, I've seen them in other videos but again they're just too expensive for a couple of gauges.

@Robin2 Thanks for those links, very useful. Those tiny motors look good but almost too small. Do you think they would actually work? The other one looks good too but the same as most of the others, I feel they are too expensive.

matthewinglis: @Robin2 Thanks for those links, very useful. Those tiny motors look good but almost too small. Do you think they would actually work?

I never bought any myself (yet) but I believe someone else on the Forum did. I have no reason to think they don't work.

...R

Well in that case, I'm tied between those tiny little ones and the 28BYJ 48 motors. Assuming I go for either of those, what drivers would I need?

Google this: gauge stepper motor driver - Scotty

matthewinglis: Well in that case, I'm tied between those tiny little ones and the 28BYJ 48 motors. Assuming I go for either of those, what drivers would I need?

The 28BYJ is a unipolar motor and is usually controlled with a ULN2003 - I have no experience of the 28BYJ but there are many Forum Threads about them.

If the tiny motors draw about 20mA they could (in theory) be driven directly from the Arduino's I/O pins but I would prefer to but some sort of buffer chip in between to protect the Arduino from voltage spikes.

...R

And what sort of power supply would I need for the 28BYJ 48 motors?

Oh yeah and I will be needing heaps of them, like at least 30 probably so assuming I will be needing at least 30, what would be the best way to go about powering both of those motors?

And what sort of power supply would I need for the 28BYJ 48 motors?

If I remember the datasheet right, they draw a bit more than the Arduino pins can deliver. So you will need to use an external power supply for them, check the current value of the motors, multiply the current by the number of motors and you are set.

There are two types of the 28BYJ 48 motors: 5V and 12V. The higher the voltage the better the control of a motor. But with your given "almost zero" load, I think it wouldn't matter. But: these motors are cheap and pretty noisy.

If you google "28BYJ 48 motor bipolar" you will find instructions how to convert those unipolar steppers to bipolar steppers. This would give you the advantage to drive the stepper with either A4988 or drv8825 drivers, which are much better drivers than the ancient UN2003 drivers.

The gauges are circle too, so I think the word you'd be looking for is diameter, not diagonal.

Maybe my English is a bit misleading but I actually meant a "diagonal" measure: e.g. NEMA 11 = 28mm square = 39mm diagonal (39mm = 28mm * 1.41) - so it's the diagonal measure which determines the size of the circle to fit in.

Oh yeah and I will be needing heaps of them, like at least 30 probably so assuming I will be needing at least 30, what would be the best way to go about powering both of those motors?

30 controlled by one or more Arduinos? Your Arduino itself will draw something like 30mA, so - if you would, say, need 5 Arduinos, you have to add 5 * 30mA to the 30 * current draw of each motor (assuming that in worst case scenario all motors have to move simultaneously).

Bunch of motor drivers needed no matter what. How many IO pins for each one? 4? That'll be more pins than a Mega will support. Perhaps a library such as: http://www.airspayce.com/mikem/arduino/AccelStepper/

Just googled the current for the 5V types:

160 mA per winding (320 mA in 4-step mode) Measured: 250mA stopped, 200 mA running fast

Source: https://arduino-info.wikispaces.com/SmallSteppers

I found another source with an overview of some flavors of 5V and 12V types:

Motors- 28BYJ-48 Stepper motor notes - grahamwideman.jpg